Your collision object should be a closed surface. At the moment the resulting collision volume looks like the attached.
As a quickie fix (also attached) you can change the volume creation mode from Ray Intersect to Minimum and add a small Offset Surface value, but in the long run it is better to get used to creating closed surfaces for your collision objects.
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Technical Discussion » Grain Flow via a Funnel
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- eetu
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Technical Discussion » Noisy point renders in Mantra
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- eetu
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Yet another thing that can help with flickering particles is vm_geofilterwidth. If a point's size is smaller than this value in raster space, say, one pixel, the point is scaled to the value specified and it's transparency modified to compensate.
E.g. if you have an opacity 1.0 particle the size of 1/100th of a pixel, it will be shaded as a particle the size of one pixel but opacity of 0.01
E.g. if you have an opacity 1.0 particle the size of 1/100th of a pixel, it will be shaded as a particle the size of one pixel but opacity of 0.01
Houdini Indie and Apprentice » How to emit smoke from a custom temperature attribute?
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- eetu
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Fun setup!
Probably the easiest is to create a temperature volume with Volume From Attribute SOP, and use that to source smoke to a smoke container. In the attached I did that in another DOP network, but you could sim it all in one go if you wanted.
(I dialled down the resolutions for faster response)
Probably the easiest is to create a temperature volume with Volume From Attribute SOP, and use that to source smoke to a smoke container. In the attached I did that in another DOP network, but you could sim it all in one go if you wanted.
(I dialled down the resolutions for faster response)
Houdini Learning Materials » Gas to solid transition.
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- eetu
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What a gorgeous visual and what an awesome problem 
I have no clear pointers, but I know you've come to the right software for the task!
Thinking about it, how about a pyro sim, but do not render the hot parts - only when the gas has cooled down? Or maybe not render even that, but use those areas to spawn particles? how you would get those to form nice rigid-ish crystalline structures I don't know.. Maybe some aggregation growth would work on that..
Anyway, good luck, and I'm eagerly awaiting what you come up with!
I have no clear pointers, but I know you've come to the right software for the task!
Thinking about it, how about a pyro sim, but do not render the hot parts - only when the gas has cooled down? Or maybe not render even that, but use those areas to spawn particles? how you would get those to form nice rigid-ish crystalline structures I don't know.. Maybe some aggregation growth would work on that..
Anyway, good luck, and I'm eagerly awaiting what you come up with!
Technical Discussion » Glass diffraction?
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- eetu
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Yeah, I can see that too, interesting. In a way that's how it should be - if you check out the relative luminances [en.wikipedia.org] of RGB components, they are calculated as Y = 0.2126 R + 0.7152 G + 0.0722 B. Looking at this, it makes sense to allocate samples according to the weight of the RGB component. What surprises me here is that Mantra is smart enough to figure out that the different refraction functions in the shader actually only affect certain components, and assigns samples to them accordingly..
… Or maybe it's something else
… Or maybe it's something else
Technical Discussion » Understanding Pz
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- eetu
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Joker386
In this project I made a simple setup for exporting custom Depth Map with original shaders (not overriding !) :wink:
Strictly speaking it's not really original shaders, as you would need to modify each and every shader used in the scene..
Technical Discussion » Understanding Pz
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- eetu
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pezetko
Other way would be exporting directly from your shader.
Sure, but in the first post he said he wasn't looking for a shader solution, that's why the jumping through hoops
Technical Discussion » Understanding Pz
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- eetu
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One way could be to route your render through COPs, like the attached. I'm unsure whether Houdini can write single-channel pngs, though.
Technical Discussion » Understanding Pz
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- eetu
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Pz is not really “distance from camera”, it is the z-coordinate of the shaded point in camera coordinates.
For a non-shader solution, and a spherical projection, you could calculate the length of the (Px, Py, Pz) vector in post. (make sure that the position is in camera coordinates). For a cylindrical projection that would be (Px, 0, Pz). For funkier projections you probably would need to grab the length of the view ray in a shader.
For a non-shader solution, and a spherical projection, you could calculate the length of the (Px, Py, Pz) vector in post. (make sure that the position is in camera coordinates). For a cylindrical projection that would be (Px, 0, Pz). For funkier projections you probably would need to grab the length of the view ray in a shader.
Houdini Indie and Apprentice » Primatives are created with flipped normals...
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- eetu
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Good point!
Houdini is right-handed, so maybe one these LH-series monitors would do the trick http://www.elive.co.nz/samsung-lh-320bx-commercial-display-T26078.php [elive.co.nz]
Houdini is right-handed, so maybe one these LH-series monitors would do the trick http://www.elive.co.nz/samsung-lh-320bx-commercial-display-T26078.php [elive.co.nz]
Houdini Lounge » OctaneRender for Houdini development preview
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- eetu
- 606 posts
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Houdini Learning Materials » Normals
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- eetu
- 606 posts
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We need to be careful here to differentiate between point and primitive normals.
I have a hunch that the original poster actually needs to see the primitive normals (Display primitive normals -button), not point normals (Display normals -button).
Point normal data is just a per-point attribute that can have any values the user wants.
Primitive normal data is intrinsic to the polygon, it is determined by vertex locations and winding. The only way to change the primitive normals without changing the geometry is by reversing the winding (with Reverse SOP as the original posted hinted at), which negates the direction of the primitive normals.
TL;DR - You need to switch on Display primitive normals.
I have a hunch that the original poster actually needs to see the primitive normals (Display primitive normals -button), not point normals (Display normals -button).
Point normal data is just a per-point attribute that can have any values the user wants.
Primitive normal data is intrinsic to the polygon, it is determined by vertex locations and winding. The only way to change the primitive normals without changing the geometry is by reversing the winding (with Reverse SOP as the original posted hinted at), which negates the direction of the primitive normals.
TL;DR - You need to switch on Display primitive normals.
Houdini Indie and Apprentice » Black stripes in rendering
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- eetu
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Work in Progress » Reaction Diffusion
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- eetu
- 606 posts
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Houdini Indie and Apprentice » PBR Metal / Roughness Shader (Unity / SD / SP Style)
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- eetu
- 606 posts
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You might want to check out Wolfwood's Disney-style BRDF, http://forums.odforce.net/topic/20682-bsdf-bonanza-ggx-microfacets-disney-brdf-and-more/ [forums.odforce.net] - it has metallicity built in.
Technical Discussion » Getting Alpha in refraction with mantra?
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- eetu
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Not trivial, but think you need to setup your shaders to pass information between each other, http://www.sidefx.com/docs/houdini14.0/vex/functions/trace#idm47446624006848 [sidefx.com]
Technical Discussion » How set and remove keyframes in python ?
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- eetu
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theratos
Thanks for your reply.
It works in part, but I do not see too much how to do really.
Moreover, in the docu I have this feature is not yet documented and/or implemented… :cry:
The links posted by mandrake show you how to do it.
You need to 1) create a keyframe 2) set its time 3) set its value 4) add it to the parameter.
All relevant methods are implemented and documented via the link above.
Houdini Indie and Apprentice » Q about the Soft Dots VEX node
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- eetu
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Houdini 14.0.263: The blur and filter paramters were removed from the softdots VOP since they were placebos and didn't actually affect the behaviour of the VOP.
\o/
Houdini Indie and Apprentice » how to draw lines betwee a group of points based on distance
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- eetu
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Houdini Indie and Apprentice » Q about the Soft Dots VEX node
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- eetu
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Yes
Not a bug in the sense that something is broken, they just seem to have the same vops interface for all the patterns that use the vop_StampPattern function, and have forgotten to remove the Blur input connector from those that do not actually use it in the code.
So, fire off a bug report!
Not a bug in the sense that something is broken, they just seem to have the same vops interface for all the patterns that use the vop_StampPattern function, and have forgotten to remove the Blur input connector from those that do not actually use it in the code.
So, fire off a bug report!
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